Pinhook Bog: Carnivorous Plants in Indiana

About fifteen thousand years ago, a block of glacial ice broke off from the retreating Laurentide ice sheet and sat buried in debris near what is now northwestern Indiana. When it finally melted, it left a depression in the glacial moraine that became a kettle lake, then slowly transformed into something stranger.

Cut off from groundwater, the lake turned acidic. Sphagnum moss formed floating mats across its surface. Pitcher plants, sundews, and rare orange-fringed orchids took hold in the sphagnum, plants that supplement nutrients by trapping and digesting insects. Tamarack trees colonized the edges. The result is a boreal bog sitting hundreds of miles south of its natural range, a glacial relic that has survived in the middle of Indiana by accident of geography. Pinhook Bog was designated a National Natural Landmark in nineteen sixty-five and is now part of Indiana Dunes National Park, one of the most ecologically unexpected places in the Midwest.